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Renamed/tweaked crystal_size -> crystal_thresh

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Our crystallization threshold doesn't really describe the bounds of an
object, and I think it's a bit easier to think of it as a threshold for
block compaction.

Heck I've already been calling this the crystallization threshold all
over the code base.

An important change is this bumps the value by 1 bytes, so
crystal_thresh now describes the smallest size of a block our write
strategy will attempt to write.

Heuristically:
- data >= crystal_thresh => compacted into blocks
- data <  crystal_thresh => stored as fragments
This commit is contained in:
Christopher Haster
2023-12-14 12:49:43 -06:00
parent 02d2919130
commit c2e3a391ff
4 changed files with 18 additions and 18 deletions
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lfs.c
+9 -9
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@@ -9505,7 +9505,7 @@ static int lfsr_ftree_carve(lfs_t *lfs,
// crystallization threshold? break into fragments
while (tag_ == LFSR_TAG_BLOCK
&& lfsr_data_size(&left_slice_) > lfs->cfg->fragment_size
&& lfsr_data_size(&left_slice_) <= lfs->cfg->crystal_size) {
&& lfsr_data_size(&left_slice_) < lfs->cfg->crystal_thresh) {
bptr_.data = lfsr_data_slice(bptr_.data,
lfs->cfg->fragment_size,
-1);
@@ -9533,7 +9533,7 @@ static int lfsr_ftree_carve(lfs_t *lfs,
// crystallization threshold? break into fragments
while (tag_ == LFSR_TAG_BLOCK
&& lfsr_data_size(&right_slice_) > lfs->cfg->fragment_size
&& lfsr_data_size(&right_slice_) <= lfs->cfg->crystal_size) {
&& lfsr_data_size(&right_slice_) < lfs->cfg->crystal_thresh) {
bptr_.data = lfsr_data_truncate(bptr_.data,
lfsr_data_size(&bptr_.data) - lfs->cfg->fragment_size);
@@ -9735,7 +9735,8 @@ static int lfsr_ftree_flush(lfs_t *lfs,
// within our tree? find left crystal neighbor
if (pos > 0
&& (lfs_soff_t)(pos - lfs->cfg->crystal_size)
&& lfs->cfg->crystal_thresh > 0
&& (lfs_soff_t)(pos - (lfs->cfg->crystal_thresh-1))
< (lfs_soff_t)lfsr_ftree_size(ftree)
&& lfsr_ftree_size(ftree) > 0
// don't bother to lookup left after the first block
@@ -9745,7 +9746,7 @@ static int lfsr_ftree_flush(lfs_t *lfs,
lfsr_bid_t weight;
lfsr_ecksum_t becksum;
int err = lfsr_ftree_lookupnext(lfs, mdir, ftree,
lfs_smax32(pos - lfs->cfg->crystal_size, 0),
lfs_smax32(pos - (lfs->cfg->crystal_thresh-1), 0),
&bid, &tag, &weight, &bptr, &becksum);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
@@ -9757,7 +9758,7 @@ static int lfsr_ftree_flush(lfs_t *lfs,
// of our crystal
if (tag == LFSR_TAG_DATA
&& bid-(weight-1)+lfsr_data_size(&bptr.data)
>= pos - lfs->cfg->crystal_size) {
>= pos - (lfs->cfg->crystal_thresh-1)) {
crystal_start = bid-(weight-1);
// otherwise our neighbor determines our crystal boundary
@@ -9791,14 +9792,14 @@ static int lfsr_ftree_flush(lfs_t *lfs,
// if we haven't already exceeded our crystallization threshold,
// find right crystal neighbor
if (crystal_end - crystal_start <= lfs->cfg->crystal_size
if (crystal_end - crystal_start < lfs->cfg->crystal_thresh
&& lfsr_ftree_size(ftree) > 0) {
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bid_t weight;
int err = lfsr_ftree_lookupnext(lfs, mdir, ftree,
lfs_min32(
crystal_start + lfs->cfg->crystal_size,
crystal_start + (lfs->cfg->crystal_thresh-1),
lfsr_ftree_size(ftree)-1),
&bid, &tag, &weight, &bptr, NULL);
if (err) {
@@ -9822,7 +9823,7 @@ static int lfsr_ftree_flush(lfs_t *lfs,
}
// below our crystallization threshold? fallback to writing fragments
if (crystal_end - crystal_start <= lfs->cfg->crystal_size) {
if (crystal_end - crystal_start < lfs->cfg->crystal_thresh) {
break;
}
@@ -10042,7 +10043,6 @@ static int lfsr_ftree_flush(lfs_t *lfs,
// prepare our block pointer
LFS_ASSERT(bptr.cksize > 0);
LFS_ASSERT(bptr.cksize >= lfs->cfg->crystal_size);
LFS_ASSERT(bptr.cksize <= lfs->cfg->block_size);
bptr.data = LFSR_DATA_DISK(
bptr.data.u.disk.block,